Climbing Weekly Volume Calculator

Climbers periodise like any other strength athlete, but climbing load is hard to pin to a single number. This calculator uses the established session-RPE method to turn each climb into Arbitrary Units, then sums your week so you can progress load deliberately instead of by feel.

How training load is quantified

Every session’s load is the product of how hard it felt and how long it lasted:

session load (AU) = session RPE (1-10) × duration (minutes)
weekly volume     = sum of all session loads

From the daily loads the tool also computes Foster’s monotony and strain, which reveal whether your week is too uniform:

monotony = mean daily load / standard deviation of daily load
strain   = weekly volume × monotony

Worked example

Three sessions logged this week:

Weekly volume: 525 + 480 + 450 = 1,455 AU

Spreading these across a 7-day week with four rest days:

• Daily loads: 0, 525, 0, 480, 0, 450, 0
• Mean daily load: 1,455 / 7 ≈ 207.9 AU
• Standard deviation: relatively high because of the zero-load rest days
• Monotony: low — a healthy pattern of hard and easy days

Contrast this with five identical 60-minute sessions all at RPE 6 (each 360 AU, weekly volume 1,800 AU): the daily loads have almost no variation, monotony rises sharply, and strain climbs even though total weekly volume is similar. This is the pattern Foster’s research associated with higher illness and injury rates.

Interpreting monotony and strain

Monotony below 1.5 is generally considered healthy — your training week has enough variation that your body can adapt and recover between sessions.

Monotony above 2.0 is the range Foster’s original studies linked to elevated illness incidence and overtraining risk. If your monotony is high, the fix is straightforward: make your sessions more varied. Add an easy mileage day between hard sessions, or cut back one session’s intensity deliberately.

Strain is weekly volume multiplied by monotony, so it rises with both more total work and less variation. Tracking strain week over week gives you a cumulative sense of how hard your training has been — a sudden spike often precedes injury or illness if recovery does not match it.

Progressing weekly load without spiking it

Once you have a few weeks of AU totals, the useful comparison is this week against your recent average — the idea behind the acute:chronic workload ratio (ACWR): acute load (this week) divided by chronic load (the average of the last four weeks). Using the example week above:

A ratio near 1.0 means you are training at your established level; the commonly used guardrail from the sports-science literature keeps the ratio roughly between 0.8 and 1.3, with sharply elevated injury risk reported above ~1.5. The second row shows how a single enthusiastic week — say, a climbing trip — can blow through that band even though every individual session felt fine. The practical rules of thumb:

• Build chronic load before acute adventures. A trip is a planned ACWR spike; the four weeks before it should ramp volume so the spike lands on a higher base.
• Progress weekly volume gradually — on the order of 5–10% per week is the guideline most coaches use — and insert a lighter consolidation week roughly every fourth week.
• After a break, restart below your old chronic load. Two weeks off drops your chronic average; returning at your previous weekly volume is itself a ratio spike.

Where session-RPE misleads climbers

• Short, savage sessions under-count. A 30-minute limit-bouldering session at RPE 9 logs only 270 AU — less than an easy hour of mileage — yet the tissue stress is far higher. Track the AU number, but never treat low AU as automatic permission for more finger-intensive work.
• RPE compresses at the top. The difference between RPE 9 and RPE 10 is physiologically enormous but only 10% numerically. If most sessions cluster at 8–9, monotony will look artificially healthy.
• Skin and weather noise. Bad friction or split tips raise perceived effort without raising true load; note the conditions so a “hard” RPE isn’t mistaken for fitness loss.

Climbing-specific considerations

The session-RPE method was developed and validated primarily in team sports and endurance athletics. Applied to climbing, a few adjustments improve accuracy:

• RPE after the session, not during it. Rate the session as a whole about 30 minutes after you finish, when the warm-up euphoria has faded and you can assess how your body actually responded to the full load.
• Boulder sessions vs. route sessions differ. A 90-minute bouldering session at RPE 8 involves very different physical demands than a 90-minute endurance route session at the same RPE. Track them separately if you want to compare load types, or track them together for overall volume management.
• Finger tendon load lags behind perceived effort. The session-RPE method captures cardiovascular and muscular effort well, but tendon stress accumulates more slowly and recovers more slowly than muscle soreness. Use the volume and monotony numbers as a guide, but listen for specific tendon signals that the AU method cannot quantify.

Sources and references

• Foster C. Monitoring training in athletes with reference to overtraining syndrome. Med Sci Sports Exerc (1998) — the origin of session-RPE load, monotony, and strain
• Foster C, et al. A new approach to monitoring exercise training. J Strength Cond Res (2001) — the session-RPE method validated

Maintained by the Gera Tools editorial team. Load = session RPE × minutes; monotony and strain follow Foster’s definitions above. The method was validated primarily in team and endurance sport, so treat climbing-specific readings as directional. Last reviewed 2026-07-02.